The invention relates to reaction systems with an aerosol reactant delivery apparatus. The reaction systems are particularly useful for the production of chemical powders.
Advances in a variety of fields have created a demand for many types of new materials. In particular, a variety of chemical powders can be used in many different processing contexts. Specifically, there is considerable interest in the application of ultrafine or nanoscale powders that are particularly advantageous for a variety of applications involving small structures or high surface area materials. This demand for ultrafine chemical powders has resulted in the development of sophisticated techniques, such as laser pyrolysis, for the production of these powders.
Some of these production techniques involve flow reactions that result in the formation of the powders in a gaseous stream. To commercially exploit these particle production processes on a practical scale, the processes must be capable of efficiently producing large quantities of particles in a reasonable period of time. These large quantities of particles must be harvested from the gaseous stream in which they are produced.
In a first aspect, the invention pertains to a reaction system comprising:
an elongated reaction chamber having an outlet along a reactant path, the reaction chamber having a cross section perpendicular to the reactant path with a dimension along a major axis greater than a dimension along a minor axis; and
an aerosol delivery apparatus comprising an aerosol generator, the aerosol delivery apparatus being connected to the reaction chamber to deliver an aerosol along the reactant path, the aerosol being elongated along the major axis of the reaction chamber relative to the extension of the aerosol along the minor axis of the reaction chamber.
In another aspect, the invention pertains to a method for producing particles, the method comprising introducing a reactant stream into a reaction chamber, the reactant stream having a cross section perpendicular to the flow direction of the reactant stream with a dimension along a major axis greater than a dimension along a minor axis and the reactant stream comprising an aerosol.
In a further aspect, the invention pertains to a reaction system comprising:
a reaction chamber having an outlet along a reactant path; and
an aerosol delivery apparatus connected to the reaction chamber to deliver an aerosol along the reaction path, the aerosol delivery apparatus comprising an ultrasonic aerosol generator having an atomization surface operably connected to an ultrasonic transducer, the atomization surface having a opening connected to a liquid flow conduit such that flow from the conduit flows along the atomization surface.
Moreover, the invention pertains to a reaction system comprising:
a reaction chamber having an outlet along a reactant path; and
an aerosol delivery apparatus comprising:
a delivery tube connected to the reaction chamber to deliver an aerosol along the reactant path;
a gas supply tube flowing into the delivery tube; and
an aerosol generator oriented to produce an aerosol along a path leading into the flow from the gas supply tube.
In another aspect, the invention pertains to a reaction system comprising:
a reaction chamber having an outlet along a reactant path; and
an aerosol delivery apparatus comprising:
a delivery tube connected to the reaction chamber to deliver an aerosol along the reactant path;
an aerosol chamber in fluid communication with the delivery tube, the aerosol chamber holding a supply of liquid;
a gas supply tube flowing into the aerosol chamber; and
an aerosol generator oriented to produce an aerosol within the aerosol chamber above the supply of liquid, the aerosol generator being connected to a liquid supply tube.
The invention further pertains to a method of producing particles, the method comprising introducing a reactant stream into a reaction chamber, the reactant stream intersecting a light beam path, the reactant stream comprising an aerosol comprising a compound that absorbs sufficient light energy to drive reactions resulting in particle formation.